Photoshop - Channels vs Layers

I’m working on some comic book art. I looked up a bunch of tutorials on comic-style coloring and most of them say to use channels. I’ve already got my flat colors on layers, figuring it would be easier to render each color if I didn’t have to reselect it every time. So why would you use channels over layers? I assume it must make something easier (maybe to backup the flat colors if you need to change it?)

I should know this stuff already, seeing as I’m a graphic designer, but my Photoshop knowledge is sadly lacking. (I am, however, an Illustrator goddess)

(This is a good example of the technique)

I always feel like I should write more. My posts are always so tiny

If it’s a spot color piece, then working in the channels will be fine, as each channel would represent each spot color. However, if it’s a 4-color piece, then the CMYK info has to stay in the channels, and you would work with the image in layers. (the short answer!)